Igniter for grenades



Patented May 4, 1937 OFFICE 2,079,178 IGNITER FOR GRENADES' Andr Valre Adrien Mortreux, Mulhouse, France, assignor to Socit Alsacienne dExplosifs (Socit aResponsabilit Limite) a Richwiller, Haut-Rhin, France -Applicatin February 12, 1935, Serial No. 6,169

In France April 10, 1934 4 Claims.

This invention relatesto an igniter for grenades, essentially characterized, on the one hand,

by the fact that the mechanical part and the pyrotechnical part are entirely independent and G5 are connected only at the time of assemblage and, on the other hand, by the fact that the pyrotechnical part constitutes a unit having a fluidtightness of its own.

Owing to these two essential features, it is possible to render the manufacture of the mechanical and pyrotechnical parts entirely independent, to keep them separately stored before their assemblage, without any prejudice to the fluidtightness of the pyrotechnical part, and, finally, tosubject the latter, separately, while it is stored or before assemblage, to tests for verifying its fluid-tightness.

Considering these remarkable advantages of the invention, it is to be remembered that, in some known types of igniters the primers and the safety or burning fuse are left uncovered in the part forming the cap of the device, so that their protection is obtained only in precarious conditions by the packings closing the said cap.

In other types also known, the fluid-tightness of the pyrotechnical part is not ensured as long as the assemblage with the mechanical part is not effected, so that any separate storage of the pyrotechnical part is practically prevented, as

Well as any test resorted to for verifying the fluid-tightness and exclusively carried out on this pyrotechnical part.

The accompanying drawing is an axial section, of a form of carrying the invention into practice, given by way of example only and in which, in order to obtain an absolutely fluid-tight pyrotechnical part, all the element of the same are enclosed within a metal case the mouth of which is finally closed by means which will be particularly described later on.

In the drawing, the entire mechanical part is known per se. It comprises,within a cap I externally screw threaded at l for screwing the igniter on the grenade,-a percussion pellet 3 which is subjected to the action of a spring 2 and carries the needle or striker 5. The locking of the percussion pellet is effected by a claw 6 which, passing in a slot of the striker, presses against the base 3 of the percussion pellet. The locking claw 6 is itself rigid with a lever 6, the pivot pin 6 of which simply rests on two bearings of a fork piece l provided on the head or cap I. This lever is locked, on the other hand, in the safety position illustrated in the figure, by means of a pin 1 passing through the lever and through a fork piece I of the head. In this position, a packing 4 is clamped between a bearing portion of the locking lever and the edge of the aperture I through which the claw (i enters the cap I.

This unit, according to the invention, is entirely independent from the purely pyrotechnical part which will now be described.

This pyrotechnical part, separately manufactured and completely fluid-tight, is entirely enclosed within a metal case l2 which carries (in the order indicated in the drawing from top to bottom), the percussion cap ID, the burning tube or delay l3, and the detonator l5.

The cap I0 rests on a support 9, the bottom of which is open and surrounded by a small quantity of a special composition I1, serving as an ignition relay.

The delay I3 is constituted by a burning tube charged with a special powder ensuring a very regular combustion and giving little residue in order that the vent holes 3 of the percussion pellet 3 should remain unobstructed. This burning tube is inserted at its upper part in a socalled delay-carrying tube H. Under the latter is threaded a cardboard tube M on which is engaged the upper part of the detonator l5 which rests against the bottom of the case I2 through a washer I6.

The various constituent elements of the pyrotechnical unit being thus placed in position within the metal case [2, the mouth of the latter is obturated in a rigorously fluid-tight manner by a cover 8 made of a waterproof and malleable material, such as metal, plastic material, etc. This cover, after interposition of a special lute, is beaded between two conical surfaces provided on the case l2 and on the delay-carrying tube II, at their upper end. Owing to the conical shape of the two clamping surfaces, the cover 8 is firmly held so that the pyrotechnical part thus closed constitutes a unit having a fluid-tightness of its own.

The assemblage of the pyrotechnical part on the mechanical part is simply effected by beading at l8, which completes the absolute fluidtightness of the device (mechanical part included). In these conditions, the operation of the igniter remains satisfactory in any circumstances. a long time in mud, no wedging of the percussion pellet can occur as is the case, in other systems, owing to the introduction of foreign matters within the cap.

The mechanical part gives to the unit thus 55 Particularly, even after remaining for 50 constituted its well known advantages. The pyrotechnioal part, constituted as a fluid-tight unit, can be preserved intact during a practical indefinite period of time, whether it is fitted on the cap or Whether it remains stored before assemblage.

I claim:

1. An igniter for grenades comprising: a mechanical part and a pyrotechnical part entirely independent and connected only at the time of assemblage, the pyrotechnical part including a fluid-tight casing, a delay-carrying element within this casing, two sets of conical surfaces provided at the upper part of the casing and of the delay-carrying element, respectively, and a cover made of waterproof and malleable material beaded between both sets of conical surfaces.

2. An igniter for grenades constituted Ioy a mechanical part and a pyrotechnical part entirely independent, the mechanical part comprising a cap with means for securing it on the grenade, a spring percussion pellet carrying a striker, means for locking said percussion pellet and comprising a claw pressed against the latter, a pivoted lever carrying said locking claw, a pin for locking said lever, the pyrotechnical part being and completely fluid-tight and comprising a case containing a percussion cap, a burning tube, a delay tube, a detonator, a delay-carrying tube enclosing the upper part of the burning tube, a cardboard tube on which is threaded the upper part of the detonator, two sets of conical surfaces provided on the upper part of the case and of the delay-carrying tube, respectively, and a waterproof and malleable cover beaded between both sets of conical surfaces and ensuring to said case a fluid-tightness of its own.

3. An igniter for grenades including a mechanism casing having an open lower end adapted to project into the grenade, a fluid tight tube forming a fuse casing and closed at its lower end, the open end of the tube being fitted in the open end of the mechanism casing, a fluid tight closure for the fuse casing, a fuse in said fuse casing, an explosive cap supported at the end of the fuse casing covered by said closure, said fuse casing being internally of inverted frustoconical form, and an inverted frusto-conical member in said tube supporting the cap, said cap being provided with a peripheral skirt held between said frusto-conical portions.

,4.'An igniter for grenades including a mechanism casing having an open lower end adapted to project into the grenade, a fluid tight tube forming a fuse casing and closed at its lower end, the open end of the tube being fitted in the open end of the mechanism casing, a fluid tight closure for the fuse casing, a fuse in said fuse casing, an explosive cap supported at the end of the fuse casing covered by said closure,

said fuse casing being internally of inverted frusto-conical form, an inverted frusto-conical member in saidtube supporting the cap, said cap being provided with a peripheral skirt held between said frusto-conical portions, and a shoulder in said mechanism casing against which the fuse casing abuts to limit its movement into the mechanism casing.

ANDRE VALERE ADRIEN MORTREUX. 

